Thermal Conductivity of the Ternary Compounds: AgMTe₂ and AgM₅Te₈ (M = Ga or In)

Abstract

We synthesized AgGaTe₂, AgGa₅Te₈, AgInTe₂, and AgIn₅Te₈ by solid-state reactions of Ag₂Te, Ga₂Te₃ or In₂Te₃, and Te, and prepared their high-density polycrystalline pellets. The thermal conductivity κ was evaluated by the laser flash method from room temperature to around 870 K. These compounds exhibited low κ, e.g. the room temperature values were 1.94, 0.54, 2.05, and 1.08 Wm⁻¹K⁻¹ for AgGaTe₂, AgGa₅Te₈, AgInTe₂, and AgIn₅Te₈, respectively. We discussed the magnitude relations of κ from the viewpoints of the crystal structure and the Debye temperature.